The U.N. special envoy to Sudan says Khartoum has not disarmed the Janjaweed militia or stopped militia attacks against civilians in the troubled region of Darfur. But he stopped short of saying that Sudan is backing the Arab fighters, as many observers have alleged.

Disagreement broke out between the U.N.'s special envoy to Sudan, Jan Pronk, and the U.S. ambassador, John Danforth, over whether or not the government is involved in attacks against its own civilians.

Human rights groups say the Sudanese government is participating in attacks against its own people. African Union monitors have also documented reports of aerial bomb attacks by the Sudanese government and repeated violations of a ceasefire agreement. But U.N. Envoy Jan Pronk told the Security Council that the government of Sudan has ceased all military operations in key areas, and he says reports of government-sponsored helicopter gunship attacks cannot be proven.

"There is no evidence whether indeed the government was attacking the rebels or whether it would be the other way around. If it would be self-defense, then it would have been in agreement with the plan of action," he said.

U.S. Ambassador John Danforth strongly disagrees.

"Well, he's just flat out wrong. Maybe he was told as of mid-August that this had stopped for a two-week period of time, I don't know. I'm sure he was attempting to be truthful, but here is a copy of the report of the ceasefire commission of the African Union. Right here," he said.

Mr. Pronk told the Security Council that some progress has been made in Sudan, but that the government should be criticized for not ending the violence perpetrated by Arab militiamen against Sudanese villagers.

"No concrete steps have been taken to bring justice or even identify any militia leaders or perpetrators of these attacks, allowing violations of human rights to continue in a climate of impunity," he said.

The Sudanese government has denied giving any support to the Janjaweed militia.

Mr. Pronk also called the humanitarian situation in Darfur "bleak," and says that more peacekeeping monitors are needed to ensure the safety of internally displaced persons.

Sudanese ambassador, Mustapha Osman Ismael, says he would welcome more African Union observers and troops, but not troops from outside Africa.

"If we talk about other forces with a different mandate, then we have a problem with this, not because we are not interested in solving the situation, but because if you put such a force - which I am sure that the U.S. and other European countries are not willing to send force in such a situation - they would complicate an already complicated situation," he said.

The Security Council is expected to deliberate the possibility of imposing sanctions. However, several council members, including veto-wielding Russia, oppose such a move. The most recent resolution on Sudan left the door open to further action if the government did not comply with its agreement to disarm the Janjaweed by the end of August. Sudan hopes to avoid sanctions by showing that it is taking steps to end the atrocities, which have resulted in tens of thousands of deaths and created more than a million refugees.